1. Field of the Invention
The present invention relates to a display device, and more particularly, to an apparatus and method for automatically controlling on-screen display (OSD) font height in a display device for supporting a multi-resolution and an OSD processor having the apparatus for automatically controlling the OSD font height.
2. Description of the Related Art
In general, television sets and monitors for computers are types of display devices. Television sets have a uniform resolution, while monitors for computers have multi-resolution, in which the number of horizontal and vertical pixels can vary. The number of horizontal and vertical pixels are changed by the frequency of an input synchronous signal and are expressed as a two-dimensional matrix of numbers of pixels in the display, for example, 640xc3x97480, 800xc3x97600, etc. A screen which operates as a user interface in the display device is referred to as an on-screen display (OSD). The OSD is another screen which occupies part of or the entire screen of the display device and displays information for interfacing with a user.
In the OSD of a display device having multi-resolution, the horizontal size of the font displayed on the screen can be maintained to be uniform by a phase-locked loop (PLL). That is, even though a horizontal resolution changes, the horizontal size of the font of the OSD does not change. However, the vertical size of the font changes when vertical resolution changes since the font height of the OSD is uniform.
In order to maintain the vertical size of the font of the OSD to be uniform in a multi-display device, the font height of the OSD is manually set in each resolution by a microprocessor. Here, the microprocessor is a controller dedicated to controlling the display device.
Therefore, in a conventional technology, the font height of the OSD must be manually set according to the vertical resolution of the display device in order to make the vertical size of the font of the OSD uniform regardless of the vertical resolution. Since the font height of the OSD is controlled by the microprocessor in software, it places a heavy burden on the microprocessor.
To solve the above problems, it is an object of the present invention to provide an apparatus for controlling on-screen display (OSD) font height in which the font height of the OSD is automatically set so that the vertical size of the OSD font can be maintained to be uniform regardless of a resolution in a display device having a multi-resolution.
It is another object of the present invention to provide a method for controlling OSD font height in which the font height of the OSD is automatically set so that the vertical size of the OSD font can be maintained to be uniform regardless of a resolution in a display device having a multi-resolution.
It is another object of the present invention to provide an OSD processor having the apparatus for controlling the OSD font height.
In accordance with one aspect of the invention, there is provided an apparatus for controlling on-screen display (OSD) font height in a display device having a multi-resolution. A horizontal line number generator generates information on the number of horizontal lines of a display region of the display device. A font height generator receives a predetermined font height reference value and the horizontal line number information, obtains automatic font height, and generates the automatic font height.
In one embodiment, the font height reference number is the number of OSD fonts to be displayed in a vertical direction in the display region.
In another aspect of the invention, there is provided a method for controlling OSD font height in a display device having a multi-resolution. A predetermined font height reference value is set. Information on the number of horizontal lines of a display region of the display device is obtained. Automatic font is obtained height using the horizontal line number information and the font height reference value.
In one embodiment, the font height reference value is the number of OSD fonts to be displayed in a vertical direction in the display region.
In accordance with a third aspect of the invention, there is provided an OSD processor for controlling an OSD in a display device having a multi-resolution. The processor includes a data receiving block for receiving the font height reference value input from an external microprocessor. A timing controller generates timing information having a vertical synchronous signal for the vertical synchronization of a signal displayed in a display region of the display device and a horizontal synchronous signal for the horizontal synchronization of a signal displayed in a display region of the display device. An OSD font height controlling apparatus obtains automatic font height using the font height reference value input from the data receiving block and the horizontal line number information of the display region and outputs the automatic font height as a font height set value. An outputting unit controls font data according to the font height set value and generates an output signal to be displayed in the display region in accordance with the timing information. The OSD font height controlling apparatus includes a horizontal line number generator for generating the horizontal line number information and a font height generator for receiving the font height reference value and the horizontal line number information and obtaining automatic font height.
According to the apparatus and method for controlling the OSD font height, it is possible to automatically maintain the vertical size of the font of the OSD regardless of resolution in the display device having the multi-resolution.